Chimpanzee culture is surprisingly diverse

Chimpanzee culture is surprisingly diverse
A chimpanzee from Goualougo in the Republic of Congo fishing for termite. (Image: Goulaougo Triangle Ape Project

Similar to us, chimpanzees use techniques learned in their daily lives to get food, for example. Observations in Africa now illustrate how diverse this form of culture is among great apes. Instead of the previously known two variants of fishing termites from their construction, researchers there discovered 38 techniques, which are combined by the chimpanzees in very different ways depending on the group and location.

The ability to learn from others is one of the most defining features of our species. It was only through this mutual transfer of skills and cultural techniques that man developed further to his present state. For a long time, traditions and culture were therefore considered to be specifically human. But in recent decades, biologists have also found evidence of such cultural learning in some other animal species, including great apes.

Chimpanzees and termite
An example of animals “with culture” are the chimpanzees. Over time, they have developed very specific techniques to get food – and these are passed on from generation to generation within the group. Such cultural techniques include, for example, cracking nuts, fishing for algae, using caves, or fishing for termites. But how diverse is the culture of chimpanzees? And are these techniques really so complex that the monkeys can only learn them from each other, instead of simply reinventing them independently of each other?

To clarify this, Christophe Boesch of the Max Planck Institute for Evolutionary Anthropology in Leipzig and his colleagues have now taken a closer look at the termite fishing of chimpanzees. Until now, it was assumed that there are only two basic variants of this – depending on whether the monkeys are dealing with a termite mound or an underground termite nest. “In above-ground fishing, a thin stick is inserted into a tunnel, deep enough for termites to bite into it,” the researchers explain. The chimpanzee then pulls out the stick and licks the termites.

38 different techniques in countless combinations

For their study, the biologists have now analyzed more than 1,600 footage of camera traps installed in the territories of ten groups of chimpanzees in different regions of Africa that had taken the animals while fishing termite. When evaluating the videos, Boesch and his team found that the chimpanzees showed far more than just the two previously known variants of this behavior. According to this, there are more than 38 different elements – from posture to the hand used to the sequence of steps – which the monkeys combine in different ways. Typically, the variants used within a group of monkeys were similar.

“The variety of techniques that chimpanzees use in the fishing of termites was a big surprise to me,” says Boesch. “Each community not only has its own unique way of fishing, but also combines a number of different technical elements in its own forms.” For example, the Wonga Wongue chimpanzees in Gabon usually lie on the side to fish termites, while the korup chimpanzees in Cameroon lean on their elbows. The chimpanzees from Goualougo in the Republic of Congo, on the other hand, are fishing. Since the ecological circumstances of these groups hardly differed, the scientists attribute these differences to traditions passed on within the groups – in other words, to different cultures.

Cultural diversity underestimated

According to Boesch and his team, the diversity of termite fishing cultures is very similar to what can be observed, for example, in human eating culture: “In Thailand and Japan, for example, the chopsticks are not only somehow shaped differently, but also the way they are kept differs,” explains Boesch. The chimpanzees are similar: “In La Belgique in Cameroon, chimpanzees form their chopsticks by cutting them to get a long brush. They then place the chopstick covered with termites on their wrists during the meal,” the researcher said. “In another place in Cameroon called Korup, on the other hand, the chimpanzees do not brush at all and use their mouths to shake the inserted stick while it is in the mound of earth.”

Even these observations of only one behavior show that the chimpanzees seem to have far more cultural diversity than previously thought. Scientists expect that many more such variations will emerge as more groups of chimpanzees are observed and compared in their behavior. One of the reasons why Boesch and his colleagues launched the project “Pan African Programme: The Cultured Chimpanzee” (PanAf) back in 2010. To do this, they have placed camera traps, collected samples and recorded ecological data at more than 40 locations in Africa. Further evaluations of this data could therefore bring some surprises.

Source: Max Planck Institute for Evolutionary Anthropology; Article: Nature Human Behaviour, doi: 10.1038/s41562-020-0890-1